Topological screen identifies hundreds of Cp190- and CTCF-dependent Drosophila chromatin insulator elements

Drosophila insulators were the first DNA elements found to regulate gene expression by delimiting chromatin contacts. We still do not know how many of them exist and what impact they have on the Drosophila genome folding. Contrary to vertebrates, there is no evidence that fly insulators block cohesin-mediated chromatin loop extrusion. Therefore, their mechanism of action remains uncertain. To bridge these gaps, we mapped chromatin contacts in Drosophila cells lacking the key insulator proteins CTCF and Cp190. With this approach, we found hundreds of insulator elements. Their study indicates that Drosophila insulators play a minor role in the overall genome folding but affect chromatin contacts locally at many loci. Our observations argue that Cp190 promotes cobinding of other insulator proteins and that the model, where Drosophila insulators block chromatin contacts by forming loops, needs revision. Our insulator catalog provides an important resource to study mechanisms of genome folding

Nbs1 is required for ATR-dependent phosphorylation events

Nijmegen breakage syndrome (NBS) is characterised by microcephaly, developmental delay, characteristic facial features, immunodeficiency and radiosensitivity. Nbs1, the protein defective in NBS, functions in ataxia telangiectasia mutated protein (ATM)-dependent signalling likely facilitating ATM phosphorylation events. While NBS shares overlapping characteristics with ataxia telangiectasia, it also has features overlapping with ATR-Seckel (ATR: ataxia-telangiectasia and Rad3-related protein) syndrome, a subclass of Seckel syndrome mutated in ATR. We show that Nbs1 also facilitates ATR-dependent phosphorylation. NBS cell lines show a similar defect in ATR phosphorylation of Chk1, c-jun and p-53 in response to UV irradiation- and hydroxyurea (HU)-induced replication stalling. They are also impaired in ubiquitination of FANCD2 after HU treatment, which is ATR dependent. Following HU-induced replication arrest, NBS and ATR-Seckel cells show similarly impaired G2/M checkpoint arrest and an impaired ability to restart DNA synthesis at stalled replication forks. Moreover, NBS cells fail to retain ATR in the nucleus following HU treatment and extraction. Our findings suggest that Nbs1 functions in both ATR- and ATM-dependent signalling. We propose that the NBS clinical features represent the result of these combined defects

The HEALing (Helping to End Addiction Long-term SM) Communities Study: Protocol for a cluster randomized trial at the community level to reduce opioid overdose deaths through implementation of an integrated set of evidence-based practices

•HEALing Communities Study is a parallel-group cluster randomized controlled trial.•Communities That Heal intervention’s goal is to reduce opioid overdose deaths.•Structured consensus decision-making strategy guided study measure development.•More than 80 study measure specifications and a common data model were developed.•The study will provide methodology and longitudinal community data for research. Opioid overdose deaths remain high in the U.S. Despite having effective interventions to prevent overdose deaths, there are numerous barriers that impede their adoption. The primary aim of the HEALing Communities Study (HCS) is to determine the impact of an intervention consisting of community-engaged, data-driven selection, and implementation of an integrated set of evidence-based practices (EBPs) on reducing opioid overdose deaths. The HCS is a four year multi-site, parallel-group, cluster randomized wait-list controlled trial. Communities (n = 67) in Kentucky, Massachusetts, New York and Ohio are randomized to active intervention (Wave 1), which starts the intervention in Year 1 or the wait-list control (Wave 2), which starts the intervention in Year 3. The HCS will test a conceptually driven framework to assist communities in selecting and adopting EBPs with three components: 1) a community engagement strategy with local coalitions to guide and implement the intervention; 2) a compendium of EBPs coupled with technical assistance; and 3) a series of communication campaigns to increase awareness and demand for EBPs and reduce stigma. An implementation science framework guides the intervention and allows for examination of the multilevel contexts that promote or impede adoption and expansion of EBPs. The primary outcome, number of opioid overdose deaths, will be compared between Wave 1 and Wave 2 communities during Year 2 of the intervention for Wave 1. Numerous secondary outcomes will be examined. The HCS is the largest community-based implementation study in the field of addiction with an ambitious goal of significantly reducing fatal opioid overdoses